package core.security;

import java.util.Collection;
import java.util.Iterator;

import org.springframework.security.access.AccessDecisionManager;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.access.SecurityConfig;
import org.springframework.security.authentication.InsufficientAuthenticationException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;

public class MyAccessDecisionManager implements AccessDecisionManager{
	public void decide( Authentication authentication, Object object, 
			Collection<ConfigAttribute> configAttributes) 
		throws AccessDeniedException, InsufficientAuthenticationException{
		
		if( configAttributes == null ) {
			return ;
		}		
		Iterator<ConfigAttribute> ite = configAttributes.iterator();		
		while( ite.hasNext()){			
			ConfigAttribute ca = ite.next();
			String needRole = ((SecurityConfig)ca).getAttribute();
			//ga 为用户所被赋予的权限。 needRole 为访问相应的资源应该具有的权限。
			for( GrantedAuthority ga: authentication.getAuthorities()){				
				if(needRole.trim().equals(ga.getAuthority().trim())){
					return;
				}				
			}			
		}
		throw new AccessDeniedException("AccessDenied");
	}
	
	public boolean supports( ConfigAttribute attribute ){
		return true;

	}
	
	public boolean supports(Class<?> clazz){
		return true;

	}
}
